/*
 * unix2dos Version 0.0
 * Bart Trzynadlowski, November 18, 2001 and June 1, 2002
 * Public domain
 */

/*
 * Converts ASCII UNIX files to DOS format by turning 10->13,10. If 13,10 or
 * just 13 is encountered, it will be skipped over. Make sure files are not
 * big enough to overflow the 32-bit counter. One byte has to be added for
 * every \n found.
 * Usage: unix2dos <files> [-v]
 * -v,-V prints version information
 *
 * Contact Bart Trzynadlowski:
 *  WWW:    http://www.dynarec.com/~bart
 *  Email:  bart@dynarec.com
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define VERSION "0.0"
#define DATE    "June 1, 2002"

int main(int argc, char **argv)
{
    FILE        *fp;
    char        *buf, *nbuf;
    unsigned    i, j, k, s, num_cr;

    if (argc <= 1)
    {
        printf("unix2dos: No input file(s) specified\n");
        exit(0);
    }
    else
    {
        for (i = 1; i < argc; i++)
        {
            if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "-V"))
            {
                printf("unix2dos: Version "VERSION", "DATE"\n");
                exit(0);
            }
        }
    }

    for (i = 1; i < argc; i++)
    {
        if ((fp = fopen(argv[i], "rb")) == NULL)
            fprintf(stderr, "unix2dos: Warning: Failed to open \"%s\"\n", argv[i]);
        else
        {
            fseek(fp, 0, SEEK_END);
            fgetpos(fp, (void *) &s);   /* get size */
            rewind(fp);
            if ((buf = malloc(s * sizeof(char))) == NULL)
                fprintf(stderr, "unix2dos: Warning: Not enough memory to load \"%s\"\n", argv[i]);
            else
            {
                fread(buf, sizeof(char), s, fp);
                fclose(fp);

                /*
                 * Count number of CRs
                 */

                for (j = num_cr = 0; j < s; j++)
                {
                    if (buf[j] == 13 && buf[j + 1] == 10)
                        j++;    /* this could be a DOS file already */
                    else if (buf[j] == 10)
                        num_cr++;
                }

                if ((nbuf = malloc((s + num_cr) * sizeof(char))) == NULL)
                {
                    fprintf(stderr, "unix2dos: Warning: Not enough memory to process \"%s\"\n", argv[i]);
                    continue;
                }
    
                for (j = k = 0; j < (s + num_cr); j++)
                {                    
                    if (buf[k] == 13 && buf[k + 1] == 10)
                    {
                        nbuf[j++] = buf[k++];
                        nbuf[j] = buf[k];
                    }
                    else if (buf[k] == 10)
                    {
                        nbuf[j++] = 13;
                        nbuf[j] = 10;
                    }
                    else
                        nbuf[j] = buf[k];
                    k++;
                }

                if ((fp = fopen(argv[i], "wb")) == NULL)
                    fprintf(stderr, "unix2dos: Warning: Failed to write back to \"%s\"\n", argv[i]);
                else
                {
                    fwrite(nbuf, sizeof(char), s + num_cr, fp);
                    fclose(fp);
                }
                free(buf);
                free(nbuf);
            }
        }
    }

    return 0;
}